JPS6222377Y2 - - Google Patents

Description

[Detailed Description of the Invention] (Industrial Application Field) The present invention relates to a printing head feeding mechanism in a printing device.

(Prior art) Conventionally, a drive wire is attached to a carriage equipped with a printing head, and the carriage is moved in the left-right direction of the printing device by rotation of a feed drum around which a portion of this wire is wound. Something,
Some have a wire simply wrapped around the outer periphery of the feed drum, and others have guide grooves bored on the outer periphery of the feed drum.

(Problem that the invention aims to solve) However, if the wire is simply wound around the outer periphery of the feed drum, the wires will repeatedly come into contact with each other over many years of use, and this friction between the wires is unavoidable. The load during winding was also large. In addition, in the case where the drive wire is wound around the guide groove of the feed drum, since this wire and the guide groove are always at the same angle, the wire moves in the axial direction of the feed drum, causing wire runout. The wire is pulled out or wound up at an angle with respect to the guide groove, resulting in high friction and a disadvantage that the wire does not move smoothly. Particularly in the case of printers, it is necessary to move the print head at high speed, and this variation in frictional load manifests itself in non-uniform print head speed, resulting in a reduction in print quality.

(Means for Solving the Problems) The features of the present invention are that the feed drum is rotatable around the feed drum, and as the drive wire moves, it is automatically slidably supported in the axial direction, and the drive wire is fitted around the outer periphery. It is located where a spiral guide groove that is wound together is bored.

(Function) Therefore, since the feed drum automatically slides in the axial direction as the drive wire moves, this sliding action ensures that the drive wire and the guide groove of the feed drum are at the same angle. Therefore, the friction between the drive wire and the guide groove is reduced.

(Example) Examples of the present invention will be described below with reference to the drawings.

In FIG. 1, printing device A includes both side plates 1 and 2.
Both ends of two guide columns 3 and 4 are pivoted between them, and a carriage 5 of a printing head is slidably attached to these guide columns. In addition, the carriage 5
A printing head (not shown) is mounted on the top surface of the printing head, and prints on paper inserted between the printing head and the platen 6 via a ribbon.

Incidentally, both ends of a drive wire 7 are connected to the carriage 5 by screws 8. Drive wire 7
is partially wound around the feed drum 13 via guide pulleys 9, 10, 11, and 12.

As shown in the second figure, the feed drum 13 is rotatably supported on a shaft 15 fixed to a support plate 14 integrally formed with the side plate 2 and slidable in the axial direction of the shaft. A single spiral guide groove 16 is bored on the outer periphery of the small diameter portion of this drum. Therefore, a portion of the drive wire 7 is wound around most of the guide groove 16.

The rotation of the feed drum 13 is performed as follows. A small gear 19 is provided coaxially with the reduction gear 18 that meshes with the drive pinion 17 of the motor, and this small gear meshes with a clutch gear 20, which is a clutch gear that can be brought into and out of contact with the clutch gear. 21 meshes with a gear 22 formed on the feed drum 13.

Therefore, due to the rotation of the drive pinion 17, the gear 2
2 rotate in conjunction with each other, and since the feed drum 13 rotates, the carriage 5 slides in the direction of arrow a by the winding action of the drive wire 7. The carriage 5 slides in the direction of the arrow a in this manner, and when the last printing is completed, the solenoid 23 is activated to release the clutch gears 20 and 21. Therefore, the feed drum 13 becomes free. At that moment, a return spring 24 whose one end is connected to the carriage 5 causes the carriage to slide in the direction opposite to the arrow and return to its original position.
When the drive wire 7 is wound up by the feed drum 13, when the clutch gears 20 and 21 are separated and the feed drum is in a free state, the feed drum 13 is moved as the drive wire 7 moves. Since it automatically slides in the axial direction, this sliding action makes the drive wire 7 and the guide groove 16 of this feed drum at the same angle, absorbing the runout of the drive wire and allowing smooth winding. be.

(Effects of the invention) In this invention, the drive wire winds around the spiral guide groove of the feed drum, and the feed drum is rotatable around the shaft and can automatically slide in the axial direction as the drive wire moves. Because the drive wire and the guide groove are at the same angle, the friction between the drive wire and the guide groove is extremely reduced, and even smoother winding is achieved. The load is also reduced, thereby preventing deterioration in print quality, and the feeding power of the print head, which is moved at high speed, can also be reduced.

[Brief explanation of the drawing]

The drawings show an embodiment of the present invention.
The figure is a perspective view of the printing device, and FIG. 2 is an enlarged sectional view of the main parts. 3, 4...Guide column, 5...Print head carriage, 7...Drive wire, 13...Feed drum, 15...Shaft, 16...Spiral guide groove.

Claims (1)

[Claims for Utility Model Registration] A feeding mechanism comprising a print head carriage movably attached to a guide column, a drive wire to which both ends of the carriage are connected, and a feed drum that drives the drive wire. In the above, the feed drum is rotatably supported on a shaft and slidably automatically in the axial direction as the drive wire moves, and has a spiral shape around which the drive wire is fitted and wound. A printing head feeding mechanism characterized in that a guide groove is formed and the printing head is rotated in conjunction with a driving means.